Polyaniline/mesoporous tungsten trioxide composite as anode electrocatalyst for high-performance microbial fuel cells

A composite, polyaniline (PANI)/mesoporous tungsten trioxide (m-WO3), was developed as a platinum-free and biocompatible anodic electrocatalyst of microbial fuel cells (MFCs). The m-WO3 was synthesized by a replicating route and PANI was loaded on the m-WO3 through the chemical oxidation of aniline. The composite was characterized by using X-ray diffraction, Fourier transform infrared spectrum, field emission scanning electron microscopy, and transmission electron microscopy. The activity of the composite as the anode electrocatalyst of MFC based on Escherichia coli (E. coli) was investigated with cyclic voltammetry, chronoamperometry, and cell discharge test. It is found that the composite exhibits a unique electrocatalytic activity. The maximum power density is 0.98 W m(-2) for MFC using the composite electrocatalyst, while only 0.76 W m(-2) and 0.48 W m(-2) for the MFC using individual m-WO3 and PANI electrocatalyst, respectively. The improved electrocatalytic activity of the composite can be ascribed to the combination of m-WO3 and PANI. The m-WO3 has good biocompatibility and PANI has good electrical conductivity. Most importantly, the combination of m-WO3 and PANI improves the electrochemical activity of PANI for proton insertion and de-insertion. (C) 2012 Elsevier B.V. All rights reserved.